Biden's comments reflected the deep political divide in the United States ahead of Nov. 8 elections that could see Republicans win control of one or both chambers of Congress.
Analysts said Republicans also could pick up the one seat they need to win control of the Senate.
But dozens of candidates also have echoed former President Donald Trump's baseless claims of fraud in his 2020 election defeat.
Trump traveled to Ohio to campaign alongside the Republican Senate nominee, J.D.
REUTERS/Hannah BeierFEARS OF ELECTION VIOLENCETrump supporters, spurred by his false election claims, have threatened and harassed election workers and voters.